Formulation and characterization of esterified xylo-oligosaccharides-stabilized oil-in-water emulsions using microchannel emulsification

A series of amphiphilically esterified xylo-oligosaccharides (xylo esters) with different fatty acids residues – decanoic acid (C-10), lauric acid (C-12) and palmitic acid (C-16) – were enzymatically modified at 60 °C for 4 h. These xylo esters were used as emulsifiers to formulate oil-in-water (O/W) emulsions by microchannel emulsification (MCE). Grooved and straight-through MCE was used to investigate the droplet generation and/or emulsion stability. Xylo ester-stabilized oil droplets were generated smoothly from microchannels arranged linearly or two dimensionally, while xylo ester-stabilized emulsions were less monodispersed owing to low surface activity of the xylo esters. The combined use of xylo esters (2.5% (w/w)) and Tween series (0.1% (w/w)) in the continuous phase can improve the monodispersity of the resultant oil. Successful droplet generation was achieved with the straight-through MCE using 2.5% (w/w) xylo laurate and 0.1% (w/w) Tween 20. The optimized combination of xylo laurate and Tween 20 inhibited coalescence and oiling off more efficiently than the droplets solely stabilized by Tween 20 during 30 days of storage.